18457912
Descripción
Test por Kathleen Lonergan, actualizado hace más de 1 año
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Creado por Kathleen Lonergan
hace más de 5 años
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Pregunta 1
Pregunta
Which of the following components does NOT dictate the electrical properties of a cell membrane?
Respuesta
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Ionic gradient across the cell membrane
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Ionic channels in the cell membrane
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Na+/K+-ATPase pump
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Osmolarity
Pregunta 2
Pregunta
Which of the following ions has a greater concentration inside the cell than outside?
Respuesta
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Potassium
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Sodium
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Chloride
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Calcium
Pregunta 3
Pregunta
Which of the following ion channels has a single, straightforward function?
Respuesta
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Voltage gated sodium ion channels
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Calcium ion channels
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Potassium ion channels
Pregunta 4
Pregunta
Voltage-gated sodium ion channels are responsible for generating action potentials. They will open when the membrane potential is _________ mV.
Respuesta
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-50
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-70
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50
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70
Pregunta 5
Pregunta
Phenytoin is a common anti-epileptic drug. Which channel does this drug block to prevent seizure activity?
Respuesta
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Voltage-gated sodium ion channels
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Voltage-gated potassium ion channels
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Voltage-gated calcium ion channels
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Ligand gated ion channels
Pregunta 6
Pregunta
Which of the following are actions of potassium ion channels? (Select all that apply)
Respuesta
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Diversifying neuronal electrical properties
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Diversifying temporal pattern of action potential trains
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Dictating different responses to synaptic input
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Intracellular signaling
Pregunta 7
Pregunta
What is the primary function of the voltage-gated delayed rectifier potassium ion channel?
Respuesta
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Repolarizing the action potential
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Depolarizing the action potential
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Setting the resting membrane potential
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Pace-making
Pregunta 8
Pregunta
There are four subtypes of calcium ion channels. Which of the following is NOT a primary function of the T-type channel?
Respuesta
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Electrical activity of neurons for sleep
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GI smooth muscles for motility
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Cardiac rhythms
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Neurotransmitter release
Pregunta 9
Pregunta
There are four subtypes of calcium ion channels. Which of the following is a function of the L-type channel?
Respuesta
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Muscle contraction
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Smooth muscles for gut motility
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Intracellular signaling
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Neurotransmitter release
Pregunta 10
Pregunta
The sodium-potassium ATPase pump has three main functions. It exports 3 Na+ for 2 K+ against their concentration gradients. Per action, one net positive charge moves outside of the cell. These maintain the ionic gradients and make the membrane inside the cell ~10-15 mV more negative than the outside. What is the third primary function?
Respuesta
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Building the osmotic gradient - inducing osmosis from inside to outside the cell.
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Building the osmotic gradient - inducing osmosis from outside to inside the cell.
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Counteracting the osmotic gradient - inhibiting osmosis from inside to outside the cell.
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Counteracting the osmotic gradient - inhibiting osmosis from outside to inside the cell.
Pregunta 11
Pregunta
In some individuals, red blood cells (RBCs) express a high density of Na/K-ATPases to counteract the unusually high permeability of the membrane to Na+. When these RBCs reach and are delayed in the vein of the spleen, what would happen to these RBCs?
Respuesta
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They may swell and rupture.
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They may shrink in volume.
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They may decrease in membrane potential (membrane inside the cell becomes more negative)
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They may increase in intracellular potassium.
Pregunta 12
Pregunta
If you have a membrane that is impermeable to both sodium and potassium ions, what is the resting membrane potential?
Respuesta
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0 mV
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-90 mV
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-70 mV
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60 mV
Pregunta 13
Pregunta
If you are observing a cell that is only permeable to potassium ions, what would you expect the equilibrium potential to be?
Respuesta
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-90 mV
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-70 mV
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60 mV
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0 mV
Pregunta 14
Pregunta
What would the membrane potential of a cell be if it were only permeable to sodium ions?
Respuesta
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60 mV
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90 mV
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-90 mV
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-60 mV
Pregunta 15
Pregunta
At resting conditions, we know that the membrane potential of a neuron is about -70 mV. From this value, we can conclude:
Respuesta
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PK > PNa at resting conditions
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PNa > PK at resting conditions
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PK = PNa at resting conditions
Pregunta 16
Pregunta
Which of the following are involved in determining the K+ equilibrium potential of a neuron? (Select all that apply)
Respuesta
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Na+ gradient
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K+ gradient
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K+ channel density
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Membrane permeability to K+
Pregunta 17
Pregunta
The equilibrium potential will change if...
Respuesta
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the ionic gradient changes
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the resting membrane potential remains constant
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sodium and potassium are moved in and out of the cell proportionately
Pregunta 18
Pregunta
You have a patient in kidney failure. They are not regulating K+ ions in the extracellular fluid. As a result, the extracellular K+ level has increased from 5 mM to 15 mM. How would this affect brain function?
Respuesta
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Action potentials will occur more easily
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Action potentials will not occur as easily
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There will be no change in action potential generation
Pregunta 19
Pregunta
The presence of leak potassium channels, which are always open:
Respuesta
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Drives the membrane potential towards the potassium equilibrium potential (-90 mV)
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Drives the membrane potential towards the potassium equilibrium potential (-70 mV)
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Drives the membrane potential towards the sodium equilibrium potential (-90 mV)
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Drives the membrane potential towards the sodium equilibrium potential (60 mV)
Pregunta 20
Pregunta
What will happen to the resting membrane potential if we block half of the leak potassium ion channels in the membrane?
Respuesta
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It will increase
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It will decrease
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It will not change
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